1. Field
The present specification relates to a mobile information terminal having a touch panel that can detect the touch or proximity of an external conductor such as a finger of a user by detecting a change in, for example, capacitance or the like and also having a display panel that can display various types of information.
2. Description of the Related Art
FIGS. 15 and 16 schematically illustrate the partial cross sectional structure of a conventional mobile information terminal having a touch panel 103 that can detect the touch or proximity of an external conductor such as a finger of a user by detecting a change in capacitance or the like and also having a display panel 104 that can display various types of information. FIG. 15 illustrates a state in which individual components have been assembled, and FIG. 16 is an exploded view when individual components are to be assembled. The individual components in FIGS. 15 and 16 are hatched to distinguish them on the drawings and not to represent their materials.
As illustrated in FIGS. 15 and 16, the conventional mobile information terminal has a display module formed by interposing a transparent touch panel 103 between a sheet of transparent window glass 102 and a display panel 104.
When incorporated into the cabinet case of the mobile information terminal, the display module is placed so that the window glass 102 is disposed at the outermost position and the display panel 104 is disposed on the inner side of the case. In the description that follows, out of the two main planes of the window glass 102, the main plane disposed on the outer side of the cabinet case when the window display module is incorporated into the cabinet case will be appropriately referred to as the outer main plane and the main plane disposed on the inner side of the cabinet case will be appropriately referred to as the inner main plane.
The size of the window glass 102 in its main plane direction is larger than the sizes of the main planes of the display panel 104 in their main plane directions. The display panel 104 and window glass 102 are placed so that the central positions of their main planes substantially match. Therefore, the outer circumferential part (referred to below as the window inner surface-side outer circumferential part 102a) of the inner main plane of the window glass 102 protrudes outward from the outer circumferential part of the display panel 104. The cabinet case of the mobile information terminal is formed with a front case 101 and a rear case 120 illustrated in FIGS. 15 and 16. The display module is incorporated into the front case 101. A circuit board 106, on which electronic circuits and the like are mounted, a battery, and the like are incorporated into the rear case 120. The front case 101 has an auxiliary plate to prevent the display module from warping due to, for example, an external force. The auxiliary plate is shaped like a plate made of, for example, stainless steel, and formed integrally with a resin wall, which is part of the front case 101.
When the front case 101, into which the display module has been incorporated, and the rear case 120, into which the circuit board 106 and the like have been incorporated, are assembled together, the mobile information terminal becomes a terminal in a substantially rectangular plate shape as illustrated in, for example, FIG. 17.
The front case 101 has a waterproof packing accepting part 101c near its outer circumferential walls that strike against the rear case 120 when the front case 101 and rear case 120 are assembled together. Similarly, the rear case 120 has a waterproof packing accepting part 120c near its outer circumferential walls that strike against the front case 101 when the front case 101 and rear case 120 are assembled together. The waterproof packing accepting parts 101c and 120c interpose a waterproof packing 121 therebetween and bring the waterproof packing 121 into tight contact with the wall surfaces of the two cases. Since the mobile information terminal is assembled with the waterproof packing 121 interposed between the waterproof packing accepting part 101c and the waterproof packing accepting part 120c in this way, it is possible to prevent water, dust, and the like from entering the interior of the mobile information terminal from a clearance formed when the front case 101 and rear case 120 are assembled together. FIG. 17 schematically illustrates the external appearance of the conventional mobile information terminal in a state in which the front case 101, into which the display module has been incorporated, and the rear case 120, into which the circuit board 106 and the like have been incorporated, are assembled together as viewed from the front side (on the same side as the display surface of the display panel) of the mobile information terminal. That is, as illustrated in FIG. 17, the outermost circumferential part of the mobile information terminal is the front-side outer circumferential edge 101b of the front case 101 and the window glass 102 is placed inside the front-side outer circumferential edge 101b. The mobile information terminal is arranged so that a display on the display panel 104 is visible through the transparent window glass 102 and transparent touch panel 103.
In the conventional mobile information terminal, the front case 101 has an opening on the side on which the display module is incorporated, as illustrated in FIGS. 15 and 16; a step (referred to below as a window glass mounting part 101a), on which the inner surface-side outer circumferential part 102a of the window glass 102 is rested when the display module is incorporated, is formed in the opening.
As for the conventional mobile information terminal, the entire circumferences of the window glass mounting part 101a and the inner surface-side outer circumferential part 102a of the window glass 102 are bonded together, for example, by the use of a double-sided adhesive tape 107. That is, as for the conventional mobile information terminal, the display module is secured to the front case 101 by bonding the entire circumferences of the window glass mounting part 101a and the inner surface-side outer circumferential part 102a of the window glass 102 together by the use of the double-sided adhesive tape 107.
In addition, Japanese Unexamined Patent Application Publication No. 2011-238027 (PTL 1), for example, discloses a mobile programmable display unit that can suppress its display panel, circuit board, and touch panel from being damaged due to an impact caused when the mobile information terminal drops or is struck against a structure or to deformation of its cabinet. The mobile programmable display unit includes a liquid crystal panel, a touch panel, a front case, a panel shock absorbing material, a panel holder, and a holder shock absorbing material. The front case has an opening. The panel shock absorbing material is placed so as to enclose the periphery of the liquid crystal panel, the cross section of which has a shape in which the ends of the liquid crystal panel are interposed; the panel shock absorbing material is supported with its front surface and side surfaces abutting the inner surfaces of the panel holder. The panel holder, formed with a bottom frame and side walls, accommodates the liquid crystal panel and the panel shock absorbing material from the rear surface side, the circumference edge of the touch panel being secured to the front of the bottom frame. In the mobile programmable display unit, the holder shock absorbing material is interposed between the front of the bottom frame and the inner surfaces of the front case.
Japanese Unexamined Patent Application Publication No. 2010-239323 (PTL 2), for example, discloses a mobile terminal apparatus that suppresses an increase in the number of parts and can prevent parts from being damaged. The mobile terminal apparatus is formed with a liquid crystal panel, a touch panel, a liquid crystal module, a circuit board, a liquid crystal flexible cable, and two spacers. The liquid crystal panel displays various images. The touch panel, which is attached to the rear surface of the liquid crystal panel, detects a contact on the liquid crystal panel. The liquid crystal module outputs an image to be displayed on the liquid crystal panel. The circuit board includes a control circuit; the circuit board is used to have the liquid crystal module output an image and to carry out an appropriate process according to the position of the contact on the touch panel. The liquid crystal flexible cable is a flexible cable made of a flexible material; it mutually connects the control circuit on the circuit board and the liquid crystal module. One of the two spacers is formed with an insulating body; it is inserted into the clearance between the circuit board and the liquid crystal flexible cable. The other spacer is stuck to a movable cabinet at a position at which the liquid crystal flexible cable is interposed between the one spacer and the other spacer. In this mobile information terminal, the rear surface of the liquid crystal panel is stuck to the movable cabinet in the vicinity of the outer circumference of the liquid crystal panel.